54d6af3 · typeable/postgresql-simple

git.iko.soy/typeable/postgresql-simple

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Documented FromField instances

54d6af3Leon P Smith14 years ago

src/Database/PostgreSQL/Simple/FromField.hs+41

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@@ -14,6 +14,8 @@ Portability: portable

15The 'FromField' typeclass, for converting a single value in a row

16returned by a SQL query into a more useful Haskell representation.

17+Note that each instance of 'FromField' is documented by a list of

18+compatible postgresql types.

18A Haskell numeric type is considered to be compatible with all

20A Haskell numeric type is considered to be compatible with all

19PostgreSQL numeric types that are less accurate than it. For instance,

21PostgreSQL numeric types that are less accurate than it. For instance,

@@ -225,14 +227,20 @@ tableColumn Field{..} = fromCol (unsafeDupablePerformIO (PQ.ftablecol result col

225format :: Field -> PQ.Format

227format :: Field -> PQ.Format

226format Field{..} = unsafeDupablePerformIO (PQ.fformat result column)

228format Field{..} = unsafeDupablePerformIO (PQ.fformat result column)

227

229

230+-- | For dealing with null values. Compatible with any postgresql type

231+-- compatible with type @a@. Note that the type is not checked if

232+-- the value is null, although it is inadvisable to rely on this

233+-- behavior.

228instance (FromField a) => FromField (Maybe a) where

234instance (FromField a) => FromField (Maybe a) where

229 fromField _ Nothing = pure Nothing

235 fromField _ Nothing = pure Nothing

230 fromField f bs = Just <$> fromField f bs

236 fromField f bs = Just <$> fromField f bs

231

237

238+-- | compatible with any data type, but the value must be null

232instance FromField Null where

239instance FromField Null where

233 fromField _ Nothing = pure Null

240 fromField _ Nothing = pure Null

234 fromField f (Just _) = returnError ConversionFailed f "data is not null"

241 fromField f (Just _) = returnError ConversionFailed f "data is not null"

235

242

243+-- | bool

236instance FromField Bool where

244instance FromField Bool where

237 fromField f bs

245 fromField f bs

238 | typeOid f /= typoid (TypeInfo.bool) = returnError Incompatible f ""

246 | typeOid f /= typoid (TypeInfo.bool) = returnError Incompatible f ""

@@ -241,6 +249,7 @@ instance FromField Bool where

241 | bs == Just "f" = pure False

249 | bs == Just "f" = pure False

242 | otherwise = returnError ConversionFailed f ""

250 | otherwise = returnError ConversionFailed f ""

243

251

252+-- | \"char\"

244instance FromField Char where

253instance FromField Char where

245 fromField f bs =

254 fromField f bs =

246 if typeOid f /= typoid (TypeInfo.char)

255 if typeOid f /= typoid (TypeInfo.char)

@@ -251,29 +260,43 @@ instance FromField Char where

251 then returnError ConversionFailed f "length not 1"

260 then returnError ConversionFailed f "length not 1"

252 else return $! (B.head bs)

261 else return $! (B.head bs)

253

262

263+-- | int2

254instance FromField Int16 where

264instance FromField Int16 where

255 fromField = atto ok16 $ signed decimal

265 fromField = atto ok16 $ signed decimal

256

266

267+-- | int2, int4

257instance FromField Int32 where

268instance FromField Int32 where

258 fromField = atto ok32 $ signed decimal

269 fromField = atto ok32 $ signed decimal

259

270

271+#if WORD_SIZE_IN_BITS < 64

272+-- | int2, int4, and if compiled as 64-bit code, int8 as well.

273+-- This library was compiled as 32-bit code.

274+#else

275+-- | int2, int4, and if compiled as 64-bit code, int8 as well.

276+-- This library was compiled as 64-bit code.

277+#endif

260instance FromField Int where

278instance FromField Int where

261 fromField = atto okInt $ signed decimal

279 fromField = atto okInt $ signed decimal

262

280

281+-- | int2, int4, int8

263instance FromField Int64 where

282instance FromField Int64 where

264 fromField = atto ok64 $ signed decimal

283 fromField = atto ok64 $ signed decimal

265

284

285+-- | int2, int4, int8

266instance FromField Integer where

286instance FromField Integer where

267 fromField = atto ok64 $ signed decimal

287 fromField = atto ok64 $ signed decimal

268

288

289+-- | int2, float4

269instance FromField Float where

290instance FromField Float where

270 fromField = atto ok (realToFrac <$> double)

291 fromField = atto ok (realToFrac <$> double)

271 where ok = mkCompats [Float4,Int2]

292 where ok = mkCompats [Float4,Int2]

272

293

294+-- | int2, int4, float4, float8

273instance FromField Double where

295instance FromField Double where

274 fromField = atto ok double

296 fromField = atto ok double

275 where ok = mkCompats [Float4,Float8,Int2,Int4]

297 where ok = mkCompats [Float4,Float8,Int2,Int4]

276

298

299+-- | int2, int4, float4, float8, numeric

277instance FromField (Ratio Integer) where

300instance FromField (Ratio Integer) where

278 fromField = atto ok rational

301 fromField = atto ok rational

279 where ok = mkCompats [Float4,Float8,Int2,Int4,Numeric]

302 where ok = mkCompats [Float4,Float8,Int2,Int4,Numeric]

@@ -281,14 +304,17 @@ instance FromField (Ratio Integer) where

281unBinary :: Binary t -> t

304unBinary :: Binary t -> t

282unBinary (Binary x) = x

305unBinary (Binary x) = x

283

306

307+-- | bytea, name, text, \"char\", bpchar, varchar, unknown

284instance FromField SB.ByteString where

308instance FromField SB.ByteString where

285 fromField f dat = if typeOid f == typoid TypeInfo.bytea

309 fromField f dat = if typeOid f == typoid TypeInfo.bytea

286 then unBinary <$> fromField f dat

310 then unBinary <$> fromField f dat

287 else doFromField f okText' (pure . B.copy) dat

311 else doFromField f okText' (pure . B.copy) dat

288

312

313+-- | oid

289instance FromField PQ.Oid where

314instance FromField PQ.Oid where

290 fromField f dat = PQ.Oid <$> atto (mkCompat Oid) decimal f dat

315 fromField f dat = PQ.Oid <$> atto (mkCompat Oid) decimal f dat

291

316

317+-- | bytea, name, text, \"char\", bpchar, varchar, unknown

292instance FromField LB.ByteString where

318instance FromField LB.ByteString where

293 fromField f dat = LB.fromChunks . (:[]) <$> fromField f dat

319 fromField f dat = LB.fromChunks . (:[]) <$> fromField f dat

294

320

@@ -298,48 +324,62 @@ unescapeBytea f str = case unsafeDupablePerformIO (PQ.unescapeBytea str) of

298 Nothing -> returnError ConversionFailed f "unescapeBytea failed"

324 Nothing -> returnError ConversionFailed f "unescapeBytea failed"

299 Just str -> pure (Binary str)

325 Just str -> pure (Binary str)

300

326

327+-- | bytea

301instance FromField (Binary SB.ByteString) where

328instance FromField (Binary SB.ByteString) where

302 fromField f dat = case format f of

329 fromField f dat = case format f of

303 PQ.Text -> doFromField f okBinary (unescapeBytea f) dat

330 PQ.Text -> doFromField f okBinary (unescapeBytea f) dat

304 PQ.Binary -> doFromField f okBinary (pure . Binary . B.copy) dat

331 PQ.Binary -> doFromField f okBinary (pure . Binary . B.copy) dat

305

332

333+-- | bytea

306instance FromField (Binary LB.ByteString) where

334instance FromField (Binary LB.ByteString) where

307 fromField f dat = Binary . LB.fromChunks . (:[]) . unBinary <$> fromField f dat

335 fromField f dat = Binary . LB.fromChunks . (:[]) . unBinary <$> fromField f dat

308

336

337+-- | name, text, \"char\", bpchar, varchar

309instance FromField ST.Text where

338instance FromField ST.Text where

310 fromField f = doFromField f okText $ (either left pure . ST.decodeUtf8')

339 fromField f = doFromField f okText $ (either left pure . ST.decodeUtf8')

311 -- FIXME: check character encoding

340 -- FIXME: check character encoding

312

341

342+-- | name, text, \"char\", bpchar, varchar

313instance FromField LT.Text where

343instance FromField LT.Text where

314 fromField f dat = LT.fromStrict <$> fromField f dat

344 fromField f dat = LT.fromStrict <$> fromField f dat

315

345

346+-- | name, text, \"char\", bpchar, varchar

316instance FromField [Char] where

347instance FromField [Char] where

317 fromField f dat = ST.unpack <$> fromField f dat

348 fromField f dat = ST.unpack <$> fromField f dat

318

349

350+-- | timestamptz

319instance FromField UTCTime where

351instance FromField UTCTime where

320 fromField = ff TypeInfo.timestamptz "UTCTime" parseUTCTime

352 fromField = ff TypeInfo.timestamptz "UTCTime" parseUTCTime

321

353

354+-- | timestamptz

322instance FromField ZonedTime where

355instance FromField ZonedTime where

323 fromField = ff TypeInfo.timestamptz "ZonedTime" parseZonedTime

356 fromField = ff TypeInfo.timestamptz "ZonedTime" parseZonedTime

324

357

358+-- | timestamp

325instance FromField LocalTime where

359instance FromField LocalTime where

326 fromField = ff TypeInfo.timestamp "LocalTime" parseLocalTime

360 fromField = ff TypeInfo.timestamp "LocalTime" parseLocalTime

327

361

362+-- | date

328instance FromField Day where

363instance FromField Day where

329 fromField = ff TypeInfo.date "Day" parseDay

364 fromField = ff TypeInfo.date "Day" parseDay

330

365

366+-- | time

331instance FromField TimeOfDay where

367instance FromField TimeOfDay where

332 fromField = ff TypeInfo.time "TimeOfDay" parseTimeOfDay

368 fromField = ff TypeInfo.time "TimeOfDay" parseTimeOfDay

333

369

370+-- | timestamptz

334instance FromField UTCTimestamp where

371instance FromField UTCTimestamp where

335 fromField = ff TypeInfo.timestamptz "UTCTimestamp" parseUTCTimestamp

372 fromField = ff TypeInfo.timestamptz "UTCTimestamp" parseUTCTimestamp

336

373

374+-- | timestamptz

337instance FromField ZonedTimestamp where

375instance FromField ZonedTimestamp where

338 fromField = ff TypeInfo.timestamptz "ZonedTimestamp" parseZonedTimestamp

376 fromField = ff TypeInfo.timestamptz "ZonedTimestamp" parseZonedTimestamp

339

377

378+-- | timestamp

340instance FromField LocalTimestamp where

379instance FromField LocalTimestamp where

341 fromField = ff TypeInfo.timestamp "LocalTimestamp" parseLocalTimestamp

380 fromField = ff TypeInfo.timestamp "LocalTimestamp" parseLocalTimestamp

342

381

382+-- | date

343instance FromField Date where

383instance FromField Date where

344 fromField = ff TypeInfo.date "Date" parseDate

384 fromField = ff TypeInfo.date "Date" parseDate

345

385

@@ -367,6 +407,7 @@ instance (FromField a, FromField b) => FromField (Either a b) where

367 fromField f dat = (Right <$> fromField f dat)

407 fromField f dat = (Right <$> fromField f dat)

368 <|> (Left <$> fromField f dat)

408 <|> (Left <$> fromField f dat)

369

409

410+-- | any postgresql array whose elements are compatible with type @a@

370instance (FromField a, Typeable a) => FromField (Vector a) where

411instance (FromField a, Typeable a) => FromField (Vector a) where

371 fromField f mdat = do

412 fromField f mdat = do

372 info <- typeInfo f

413 info <- typeInfo f